Pressure control



, Patented June 18, 1946 UNITED STATES PATENT OFFICE,

PRESSURE CONTROL Lewis G. Hufiord, Redondo Beach, Calif. Application March 22, 1944, Serial No. 527,582

My invention relates to a pressure control, and more particularly to a control for an electric switch that is dependent upon continued fluid pressure.

An object of the invention is to provide an automatic control that is subject to the pressure in an oiling system, whereby an electric circuit may be brokenin' case the pressure in the oiling system falls below a given point.

Another object of the invention is to provide automatic means to break the ignition of an internal combustion engine in case the oiling system-fails because of lack of oil, although it is to be understood that the present control is adaptable for other types of mechanism than internal combustion engines.

A further object of the invention is to provide manual means for initially closing the circuit of an apparatus of the character hereinbefore mentioned, in order to be able to start the apparatus even though there is no pressure in the oiling system, and then to be able to switch the control over to its automatic position in which the circuit'is automatically broken in case the pressure in the oiling system becomes reduced to a predetermined point.

My invention also has for its objects to provide such means that are positive in operation, convenient inuse, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The inventionalso comprises novel details 01 construction and novel combinations and arrangements of parts, which will more fullyappear in the course of thefollowing description. However, the drawing merely shows and the following descriptionmerely describes one embodiment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

Fig. 1 is a face view of an embodiment of the foregoing objects, with a face plate shown in F18; 2 removed.

Fig. 2 is a vertical section taken along the line 2-2 of Fig. 1.

Fig. 3 is a transverse section taken along the line 3-3 of Fig. 2, looking in the direction of the arrows.

Fig. 4 is a curved section taken along the semicircular line 4-4 of Fig. l.

Referring more in detail to the drawing, the reference number 4 generally designates a hous ing mounted upon a face plate 5. It is the face 4 Claims. (oi. zoo-81.5)

plate 5 that has been removed from Fig. l. Normally bolts 6 hold the housing 4 and face plate 5 together. The bolts 6 also extend through a back plate I and hold a diaphragm 8 clamped between the body of the housing 4 and the back plate 7.

The diaphragm 8 has an enlarged, angular rim 9 that fits in complementary recesses I0 and I! in the opposed faces of the housing 4 and back plate I. The back plate 1 has a threaded nipple 83 for connection with a line from an oiling system, to convey pressure through passage M in the nipple against the back of the diaphragm I. The diaphragm 8 has a pad I5 on its rear face which at rest (as shown in the drawing), closes the passage i l.

Insulation it extends around the inner face of the housing i. The insulation i 6 is'thickened at the bottom, as shown at ii, in which is im bedded inner ends of wires l8 and IS, in an electric circuit, Contact fingers 20 and H are respectively connected with the wires l8 and IQ. Contacts 22 are mounted on opposed faces of the fingers 20 and 2 i.

An abutment member Eilengaging the back of the finger '26 has a flange 24 imbedded in the pad !5 of the diaphragm t.

Journaled in the housing 4 is a pivot pin 25. Coil spring 26 around the enlarged inner end of the pin 25 abouts against a collar 21' on the stem, and against the opposed inner face of the housing 4, to draw the pin 25 inward with respect to the housing 5. The normal position of the fing er 20 is as shown by the broken lines in Fig. 2. The pressure of the spring 25 moves the finger 20 to its full line position in Fig 2, when permitted by the adjustment hereinafter described.

A manual switch lever 28 is fastened on the pin 25, a suggested at 29. The front face of the housing 4 has a three-step adjusting are 30 provided with recesses 35, 32 and 33. A ball 34 in a recess 35 in the back of the switch 1ever28 is urged by a coil spring 36 into one of the recesses 31, 32 or 33 or rolls along the three-step are It between the recesses.

Th are 30 preferably has three steps or three elevations 5|, 52 and 53, as best shown in Fig. 4. When the lever 28 is in engagement with the highest elevation 53, the pin 25 is drawn outward from the housing 4 sufiiciently for 'the finger 20 to resiliently spring back to its normal broken line position in Fig. 2, which is the inoperative position. The second highest elevation 52 permits the lever 28 to be moved inwardly toward the housing 4 by the spring 26, until thepin acoaaes 3 25 is in the position shown in Fig. 2 and thereby the finger 20 is moved to the full line position shown in Fig. 2, which is the normal running position. The lowest elevation permits the lever 28 to be moved even farther inward, under the influence of the spring 26 until the contacts 22 are in engagement with each other by reason of bending the finger toward the finger M, which is the starting position.

A pointer 38 may be mounted on the lever 28 to register with the words Start, Run and Oil, as shown at 39, 40 and M onthe face of the housing 4. This indicates the different positions of the lever 28 just described, The spring-urged detent 34 provides a means for indicating to the operator the diflerent positions.

In the operation of my present device, by switching the lever 28 to a position in which the ball 34 is in the recess 33 on the highest elevation 53, the lever 28 is moved to the left in Fig. 2, against the action of the sprin 26. Thi permitsthe finger 20 to swing to the left in Fig. 2,

" as shown in broken lines, so that the circuit is eilectively broken irrespective of what pressure exists'in the passage I4.

When the switch lever 28 is moved to a position in which the ball 34 is in engagement with the recess 3|, the lever 28 moves to itsclosest position with respect to the housing 4. In this position the spring 26 causes the finger 20 to move to a position in which the contacts 22 are in engagement with each other, so that the circuit is closed irrespective of what pressure exists in the passage H,

The inbetween position of the lever 28, as shown in the drawing, illustrates the ball 34 as being in the recess 32. This is the normal running position, in which the contacts 22 are in engagement with each other if the pressure in the passage l4 rises sufficiently to flex the clastic diaphragm to a point where the finger 2| is bent to the left in Fig. 2, until the contacts 22 are in engagement. If the pressure in the pas- .sage I 4 falls below that point, the contacts are separated by the inherent resilience of the finger 2|. The fall in the fluid pressure in the passage 14 indicates trouble. This decline in the pressure breaks the circuit containing the wires l8 and I9. i

If my control is connected with an internal combustion engine, the circuit Would'be the ignition circuit, Thus, if the oil pressure fell below a certain point. the ignition circuit would be automatically broken, thus stopping the engine, so that the trouble could be corrected.

While I have illustrated and described what 1 and away from each other, diaphragm means arranged to seal off the contacts in a particular space in the housing, means to supply fluid under pressure to the housing at the opposite side of the diaphragm from the contacts, and means opening the contacts to a point where the diaphragm cannot close same though actuated by one of said contacts out of reach of the .other 4 fluid pressure, whereby to break the circuit despite the fluid pressure, said means including a pin journaled in said housing, tension means to cause said pin to oppose the resilient movement of one of said contacts relative to the other, a lever connected to said pin, and a graduated body on said housing and cooperating with said lever to control manually the position of 'one 01' said contacts relative to and independently of the other contact. v

2. In a machine having an electric circuit and having means for maintaining a supply of lubrieating oil under pressure, a housing, a flexible diaphragm in the housing sealing the interior thereof into separate compartments against the passage of fluid from one compartment to the other, the housing having a connection with said stronger than the contact support that it actuates, means to operate said pin, including a lever, a body graduated in different planes secured to said housing and having indentations, said lever manually movable on said body and having spring-pressed means to engage said indentations and hold said lever in any one of three positions, to-wit: to move one of the .contact supports to a circuit closing position, regardless of the oil pressure; to maintain the one contact in position to be engaged bythe other contact when under the influence of the oil pressure; and to move contact.

3. A control device comprising a housing, resilient electrical contacts in the housing movable toward and away from each other, diaphragm means to seal oil the contacts in the housing, means to supply fluid pressure to the housing at the opposite side of the diaphragm from the contacts, and means to control the position of one of said contacts relative to the other, to move the same to a circuit closing position regardless'of pressure, to maintain said contact in position to be engaged by the other contact when under pressure and to cause said contact to move out of reach of the other contact, said means including a pin, tension means to oppose the resilient movement of one of said contacts relative to the other, a lever connected to said pin, and means on said housing and co-operating with said lever to control manually the position of said one contact relative to and independently of the other contact. Y

4. In a machine having an electric circuit and having means for maintaining a supply of lubricating oil under pressure, a housing, a flexible diaphragm in the housing sealing the interior thereof into separate compartments against the passage of fluid from one compartment to the other, the housing having a connection with said means to supply oil under pressure to the compartment at one side of the diaphragm, electrical contact means in said circuit disposed in g the other compartment, the contact means being vmovable to closed and open positions and comprisingresiiient contact support means mounted to move by its inherent resilience to a predeter mined position, a pin journaled in said housing, spring means influencing said pin to oppose the resilient tendency of one of said contacts to move away irom the other contact, and means to control the inward and outward movement of said pin and the roiative movement of said contacts, comprising a lever secured to said pin, a body graduated to different planes mounted on said housing, and the planes provided with indentations, and a spring-pressed member carried by said lever and engageabie in said indentations.

LEWIS C. HUFF'ORD. 

